The purpose of this project is to develop novel assays for T cell function that are easy to perform and give quantitative data on T cell reactivity in human peripheral blood samples. In particular, the design should incorporate a minimization of complex or temperature-sensitive materials as well as the potential for automation. These features should facilitate the use of the novel assay in unfavorable conditions in the field. Thus, these assays could be applicable in the analysis of samples from AIDS vaccine clinical trials in third-world countries. These assays that are currently under development include: 1) the T blast assay - which allows the enumeration of antigen-reactive T cells by development of clusters of T cell blasts and 2) non-radioactive cytokine bioassays. These could allow the study of both antigen reactivity and cytokine production in human peripheral blood samples. Also, plans are being formulated for the development of a simplified cytolytic T cell assay that does not require radioactivity and can be used with peripheral blood samples.